This is great! It's obviously over-the-top, but that just makes the point all the stronger. It's zany, too. I am a big fan.

The only places it looks obviously manip'd to my eye are the limbs (especially where the front one meets the main body), the horn (the lighting), and some of the bubbles (too regular). Gorgeous water, too.

Awesome work, but I think if the Rhino really were to become aquatic, it'd have bigger fins and perhaps even a smaller head and horns to be fit for swimming and moving. Also, the shell looks more like it belongs to a tortoise and not a turtle- correct me if I'm wrong.